This invention relates to a novel and improved method and instrumentation for the blind injection of medical solutions into one or more predetermined locations within a cavity of the body; and more particularly relates to a novel method and apparatus for occluding the fallopian tubes for sterilization of females in a rapid, safe and efficient manner.
Various methods and techniques have been devised and utilized over the years for sterilization or birth control of females. Innumerable types of contraceptives have been suggested and utilized as a temporary means of birth control but have never been found to be completely effective. Similarly, although certain drugs have been found to be an effective means of temporary sterilization or birth control, side effects of these drugs is at best uncertain. In any case, none of the temporary means of sterilization or birth control proposed is capable of providing longterm sterilization and requires either regular use of dosages in order to be effective. Of course, surgical procedures are in use which will achieve permanent sterilization but in most all cases cannot be resorted to as means of longterm temporary sterilization or birth control.
It is well known that a common cause of sterility is the blockage of the Fallopian tubes by inflammation, and it follows that an ideal method of sterilization would be the transvaginal introduction of an inflammatory agent which would occlude the cornul portion of the tubual lumen, since at this location in female mammals there is found a narrow canal on opposite sides of the uterus which is surrounded by dense and highly toxic uterine muscles resembling a sphincter. The principal difficulties inherent in this approach to sterilization are not only the utilization of an inflammatory agent which will reliably produce the necessary occlusion but in the method and instrumentation of introducing the agent in a blind fashion so as to assure in each case that the injection is made at precisely the proper location without pain or injury to the patient. Moreover, it is highly desirable that the inflammatory agent be injected on both sides of the uterus.
Studies conducted to date have demonstrated the ability to inject under direct vision into the uterine cornus of certain female mammals a sclerosing agent which would produce scarring in animal tissue, i.e., a chronic lesion over fairly extended time periods. Here, reference is made to my earlier publications jointly with other authors which describe earlier work done in the field of female sterilization: "Transvaginal Delivery of Sterilizing Chemicals" Human Sterilization, (1972); "Chemical Occlusion at the Uterotubal Junction in Monkeys," American Journal of Obtetrics Gynec., (1972); "Evaluation of Experimental Methods of Occluding the Uterotubal Junction," Female Sterilization (1972). In the selection of a sclerosing agent, particularly good results were realized through the use of paraformaldelhyde or polyoxymethylene adminstered in an alcohol solution and injected into the uterine wall in the region of the Fallopian tubes ostra. Specifically, the results of more recent testing with the use of paraformaldehyde solutions revealed longterm sterilization for periods as great as six weeks with little or no apparent side effects, and made apparent the desirability for a safe, reliable method and instrument for bilateral injection of the solution at precise locations in the uterus without benefit of visibility or physical touch and solely by manipulation and control of the instrument externally of the vagina.
Various types of needle assemblies have been devised in the past for blind insertion into a cavity of the body including a needle guide so designed as to guide advancement of the needle along a predetermined angle of incidence into particular areas or tissue portions in the cavity. In this relation obstetrical needles have been devised for insertion into the uterus or other cavities but are not satisfactory for use in the sterilization procedures accomplished in accordance with the present invention. Here, for purposes of illustration, reference is made to U.S. Pat. Nos. 2,700,385 to Ortiz and 2,712,314; 2,740,404, both to Kohl. Generally, these and other prior art devices are not capable of blind injection of inflammatory agents into precise locations in the uterus so as to promote scarring of the tissue and resultant sterilization in a safe dependable manner. In addition, none comprises a needle assembly with a disposable cartridge which can be manipulated to follow the sequence of steps required in carrying out the sterilization procedure of the present invention.